Spread throughout deep space are galaxies– clusters of stars, planets, gas and dust bunched together.
Like individuals, galaxies vary. They are available in various shapes and sizes.
Artists idea of a face-on take a look at the Milky Way. Keep in mind the spiral arms. Credit: NASA/JPL-Caltech/R. Hurt (SSC).
Earth is in the Milky Way, a spiral galaxy; its stars cluster in spiral arms that swirl around the galaxys center.
Other galaxies are elliptical– kind of egg-shaped– and some are irregular, with a range of shapes.
From Canyonlands National Park in Utah, a view of a small part of the Milky Way. Credit: National Park Service/Emily Ogden.
Counting the galaxies.
Prior to determining the variety of stars in deep space, astronomers first need to approximate the variety of galaxies.
To do that, they take very comprehensive images of small parts of the sky and count all the galaxies they see in those photos.
That number is then multiplied by the variety of images required to photograph the whole sky.
The response: There are around 2,000,000,000,000 galaxies in deep space– thats 2 trillion.
15,000 galaxies appear as small dots and blots in this NASA photograph of the nighttime sky. Each galaxy contains billions of stars. Credit: NASA/ESA/P. Oesch/M. Montes.
Counting the stars.
Astronomers dont know precisely the number of stars remain in each of those 2 trillion galaxies. Many are so remote, theres no chance to inform precisely.
We can make a great guess at the number of stars in our own Milky Way. Those stars are diverse, too, and can be found in a wide range of sizes and colors.
Our Sun, a white star, is medium-size, medium-weight and medium-hot: 27 million degrees Fahrenheit at its center (15 million degrees Celsius).
Larger, heavier and hotter stars tend to be blue, like Vega in the constellation Lyra. Smaller sized, lighter and dimmer stars are usually red, like Proxima Centauri. Except for the Sun, its the closest star to us.
Artists idea of a red dwarf star with an exoplanet in orbit. About two-thirds of the stars in the Milky Way are red overshadows.
An incredible number.
Red, blue and white stars release different quantities of light. By measuring that starlight– particularly, its color and brightness– astronomers can approximate how numerous stars our galaxy holds.
With that technique, they discovered the Milky Way has about 100 billion stars– 100,000,000,000.
Now the next action. Utilizing the Milky Way as our design, we can increase the variety of stars in a typical galaxy (100 billion) by the variety of galaxies in the universe (2 trillion).
The response is an absolutely astounding number. There are around 200 billion trillion stars in the universe. Or, to put it another way, 200 sextillion.
Thats 200,000,000,000,000,000,000,000!
The number is so huge, its difficult to picture. However try this: Its about 10 times the variety of cups of water in all the oceans of Earth.
Consider that the next time youre looking at the night sky– and then question what may be happening on the trillions of worlds orbiting all those stars.
NASA video. Our Milky Way galaxy: How huge is area?
Written by Brian Jackson, Associate Professor of Astronomy, Boise State University.
This article was very first published in The Conversation.
Each galaxy contains billions of stars. Smaller, lighter and dimmer stars are generally red, like Proxima Centauri. Artists principle of a red dwarf star with an exoplanet in orbit. About two-thirds of the stars in the Milky Way are red dwarfs. There are around 200 billion trillion stars in the universe.
Astronomers have actually discovered a method to approximate the number of stars in the universe.
Look up at the sky on a clear night, and youll see thousands of stars– about 6,000 or so.
However thats just a tiny fraction of all the stars out there. The rest are too far for us to see them.
The Sun is a star, the closest one to us– 93 million miles away.
The universe, galaxies, stars
Astronomers like me have figured out how to approximate the total number of stars in the universe, which is everything that exists.